The study of genetic traits in intact animals has been facilitated by transgenic and gene-targeting (gene-disruption/ knockout and gene-duplication) experiments in which desired genetic changes are made in the germ-line. Thus, the creation of genetically engineered transgenic mouse and rat models and gene-targeted mouse strains has provided tremendous advancements in biomedical research. The technology to insert, delete, replace, and/or mutate genomic sequences in the living animal models or in specific tissues of interest has provided enhanced opportunities to reproduce or delete the pathogenesis of human diseases and/or to identify their molecular targets. If the gene of interest is quantitive such as blood pressure and cardiovascular function, it requires great efforts to maintain uniform genetic background. The transgenic and gene-targeting technologies provide novel model systems for undertaking the type of investigation through analysis that have either decreased (gene-knockout) or increased (gene-implication) gene copies at the normal chromosomal location controlled by natural regulatory gene sequences. The primary goal of the Transgenic and Gene-Targeted Animal COBRE Core is to provide each investigator an access to our knowledge, resources, and technical support to establish breeding pairs, genotyping, maintain, and generate new colonies of genetically manipulated mouse and rat colonies. For the Phase 111 period, the Transgenic and Gene-Targeted Animal Core facility will be a major resource that will continue providing genetically established mouse and rat models for hypertension and cardiovascular and renal research to the COBRE investigators and others at the Tulane University Health Sciences Center. The core will provide the service, education, and training to our investigators, research fellows, students, and staff to establish, maintain and generate new breeding pairs, genotyping, and characterization of genetically manipulated mice and rat colonies.